In general, apparatuses for displaying images are known. One type of display device is the large screen direct view television. Large screen direct view televisions can be cathode ray tube (CRT) displays, liquid crystal displays (LCD), or plasma screen displays, and can have diagonal sizes of up to 5 feet. Large screen direct view televisions provide high picture quality, but are very expensive. The cost of large screen direct view televisions increases dramatically with increased size.
An alternative to large screen televisions is the projection television. Projection televisions include a screen and a projector mounted either in front of or behind the screen. Projection televisions for home use can have large diagonal sizes, and provide a relatively large field of view at a reasonable cost. However, the field of view provided by projection televisions is limited to the area of the projection screen.
Public movie theaters use projection systems, typically film projectors, to display images on a screen at the front of a theater. These projection systems provide high quality images on the screen. However, the field of view in theater projection systems is also limited to the area of the projection screen.
The above systems are all capable of displaying images of high quality, but have limited visual effect because the viewing experience is limited to a relatively small region defined by the display screen. The peripheral regions of a human's sight provide an avenue to convey visual information that is not utilized by the conventional systems.
FIG. 1 illustrates a vertical range of vision diagram for a human viewer, the range of vision establishing a human's field of vision. FIG. 2 illustrates the regions of varying visual acuity for a human's left and right eyes while viewing an image together. The inner region 30 of the diagram is a region of relatively high visual acuity. The shaded outer region 32 in the diagram illustrates the portion of a person's field of vision that is of low acuity, but which is also very sensitive to changes in brightness and motion. The outer region 32 includes the peripheral vision. As illustrated by FIG. 2, the acuity of the eyes decreases with increasing angular deviation (both horizontal and vertical) from the line of sight .
As shown in FIGS. 1 and 2, the human's range of vision is very wide, and can extend beyond a 180 degree field. It would therefore be desirable to present imagery across the entire range of vision when displaying, for example, an entertainment program. However, because of the decreasing acuity with increasing distance from the line of sight , it may not be desirable to provide high resolution imagery in the peripheral regions of a human's vision. This is true because it is generally more costly to present high resolution imagery, and the human viewer cannot perceive the high resolution in the peripheral region. Further, the cost to store, process, and transfer high resolution image signals further increases the cost and complexity of display devices.
There is therefore a need for a method of displaying images that presents images to an expanded region of a viewer's field of vision. There is also a need for expanding the field of view without incurring undue cost or complexity.